1. Field of the Invention
The present invention relates to an air cleaner for a motorcycle, and particularly to an air cleaner having an improved air intake duct.
2. Description of the Background Art
In an air cleaner of a motorcycle, the outside air drawn in through an air intake duct is supplied to a carburetor through a filter provided in the air cleaner case. Conventionally, the air intake duct has been formed in a shape having a large curved portion, for example a trap shape, for preventing water droplets from entering the air cleaner case. Accordingly, the air intake duct has been fabricated separately from the air cleaner case. The disadvantages of this construction are that the number of individual parts is increased, and consequently, the assembly of these parts takes considerable time. Further, the necessary capacity of the air cleaner is difficult to ensure because of the need to maintain a space in which the air intake duct may be placed.
A technique using part of an air cleaner case as an air intake duct is disclosed in Japanese Utility Model Laid-open No. SHO 64-53453. In this technique, the upper wall of the air cleaner case serves as the bottom wall of the air intake duct, and the opening of the air intake duct is directed toward the rear of the motorcycle. The disadvantage of this technique is that it is easy for water droplets to enter the air cleaner case by moving along the bottom wall of the air intake duct.